class My(object):

    def __init__(self,a,b):
        print('begin init')
        self.a=a
        self.b=b

    def __new__(cls, *args):
        print(cls.__name__)
        print('begin new ')

        return object.__new__(cls)

o=My(3,4)
print('只执行一次',o.a,__name__)
if __name__ == '__main__':
    print("hi",__name__)
